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Effects of vitamin d plus calcium supplements on pharmacokinetics of isoflavones in thai postmenopausal women.

Teekachunhatean S, Pongnad P, Rojanasthein N, Manorot M, Sangdee C - Evid Based Complement Alternat Med (2011)

Bottom Line: The objective of this study was to determine the effects of vitamin D(3) plus calcium supplements (D(3)-calcium) on pharmacokinetics of isoflavones in Thai postmenopausal women.T(max) of daidzein and genistein after regimen B was significantly longer than that of regimen A.Other pharmacokinetic parameters of daidzein and genistein obtained following the three regimens were not significantly different.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.

ABSTRACT
The objective of this study was to determine the effects of vitamin D(3) plus calcium supplements (D(3)-calcium) on pharmacokinetics of isoflavones in Thai postmenopausal women. This study was an open-labeled, randomized three-phase crossover study. Twelve healthy subjects were randomized to receive one of the following regimens: (a) a single dose of isoflavones, (b) a single dose of isoflavones, and D(3)-calcium, or (c) continuous D(3)-calcium for 7 days followed by a single dose of isoflavones on the 8th day. After a washout period, subjects were switched to receive the 2 remaining regimens according to their randomized sequences. Blood samples were collected before dose and at specific time points until 32 hours after isoflavone administration. Plasma was treated with β-glucuronidase/sulfatase to hydrolyze glucuronide and sulfate conjugates of daidzein and genistein. Plasma concentrations of daidzein and genistein were determined by high performance liquid chromatography. The estimated pharmacokinetic parameters of isoflavones were time to maximal plasma concentration (T(max)), maximal plasma concentration (C(max)), half-life (t(1/2)) and area under the plasma concentration-time curve (AUC). T(max) of daidzein and genistein after regimen B was significantly longer than that of regimen A. Other pharmacokinetic parameters of daidzein and genistein obtained following the three regimens were not significantly different.

No MeSH data available.


Chromatogram of plasma sample containing 2,400 ng/mL of daidzein (retention time, k = 9.980 min) and genistein (k = 12.541 minutes) and 4,000 ng/mL of fluorescein (internal standard, k = 6.425 minutes).
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fig1: Chromatogram of plasma sample containing 2,400 ng/mL of daidzein (retention time, k = 9.980 min) and genistein (k = 12.541 minutes) and 4,000 ng/mL of fluorescein (internal standard, k = 6.425 minutes).

Mentions: The assay was modified from protein precipitation procedure. Briefly, after enzymatic hydrolysis, plasma samples were spiked with 10 μL of internal standard (IS, 50,000 ng/mL fluorescein in 80% methanol) and then deproteinated by mixing plasma samples with 500 μL acetonitrile, vortex mixing for 30 sec and centrifuged at 14,000 rpm for 10 min, respectively. An aliquot of the supernatant was removed and evaporated for 2 h at 60°C. The residue was dissolved in 50 μL of the mobile phase, and 5 μL of the sample was injected onto the HPLC system. Chromatogram of plasma containing daidzein, genistein, and IS is presented in Figure 1. The isoflavone contents of samples were determined by using a calibration curve of peak height ratios of isoflavones (daidzein and genistein) and IS versus respective isoflavone concentrations (37.5, 75, 150, 300, 600, 1200, and 2400 ng/mL) with the use of linear regression. The linear regression analysis of peak height ratios of isoflavones versus isoflavone concentrations consistently yielded coefficients of determinant (r2) of 0.997 or better.


Effects of vitamin d plus calcium supplements on pharmacokinetics of isoflavones in thai postmenopausal women.

Teekachunhatean S, Pongnad P, Rojanasthein N, Manorot M, Sangdee C - Evid Based Complement Alternat Med (2011)

Chromatogram of plasma sample containing 2,400 ng/mL of daidzein (retention time, k = 9.980 min) and genistein (k = 12.541 minutes) and 4,000 ng/mL of fluorescein (internal standard, k = 6.425 minutes).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3108160&req=5

fig1: Chromatogram of plasma sample containing 2,400 ng/mL of daidzein (retention time, k = 9.980 min) and genistein (k = 12.541 minutes) and 4,000 ng/mL of fluorescein (internal standard, k = 6.425 minutes).
Mentions: The assay was modified from protein precipitation procedure. Briefly, after enzymatic hydrolysis, plasma samples were spiked with 10 μL of internal standard (IS, 50,000 ng/mL fluorescein in 80% methanol) and then deproteinated by mixing plasma samples with 500 μL acetonitrile, vortex mixing for 30 sec and centrifuged at 14,000 rpm for 10 min, respectively. An aliquot of the supernatant was removed and evaporated for 2 h at 60°C. The residue was dissolved in 50 μL of the mobile phase, and 5 μL of the sample was injected onto the HPLC system. Chromatogram of plasma containing daidzein, genistein, and IS is presented in Figure 1. The isoflavone contents of samples were determined by using a calibration curve of peak height ratios of isoflavones (daidzein and genistein) and IS versus respective isoflavone concentrations (37.5, 75, 150, 300, 600, 1200, and 2400 ng/mL) with the use of linear regression. The linear regression analysis of peak height ratios of isoflavones versus isoflavone concentrations consistently yielded coefficients of determinant (r2) of 0.997 or better.

Bottom Line: The objective of this study was to determine the effects of vitamin D(3) plus calcium supplements (D(3)-calcium) on pharmacokinetics of isoflavones in Thai postmenopausal women.T(max) of daidzein and genistein after regimen B was significantly longer than that of regimen A.Other pharmacokinetic parameters of daidzein and genistein obtained following the three regimens were not significantly different.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.

ABSTRACT
The objective of this study was to determine the effects of vitamin D(3) plus calcium supplements (D(3)-calcium) on pharmacokinetics of isoflavones in Thai postmenopausal women. This study was an open-labeled, randomized three-phase crossover study. Twelve healthy subjects were randomized to receive one of the following regimens: (a) a single dose of isoflavones, (b) a single dose of isoflavones, and D(3)-calcium, or (c) continuous D(3)-calcium for 7 days followed by a single dose of isoflavones on the 8th day. After a washout period, subjects were switched to receive the 2 remaining regimens according to their randomized sequences. Blood samples were collected before dose and at specific time points until 32 hours after isoflavone administration. Plasma was treated with β-glucuronidase/sulfatase to hydrolyze glucuronide and sulfate conjugates of daidzein and genistein. Plasma concentrations of daidzein and genistein were determined by high performance liquid chromatography. The estimated pharmacokinetic parameters of isoflavones were time to maximal plasma concentration (T(max)), maximal plasma concentration (C(max)), half-life (t(1/2)) and area under the plasma concentration-time curve (AUC). T(max) of daidzein and genistein after regimen B was significantly longer than that of regimen A. Other pharmacokinetic parameters of daidzein and genistein obtained following the three regimens were not significantly different.

No MeSH data available.